\begin{tikzpicture}
    \draw (2, 0) circle [x radius=2, y radius=1];
    \node at (2, -1.5) {正数集合};
    \draw (8,0) circle [x radius=2, y radius=1];
    \node at (8, -1.5) {负数集合};

    \node at (0.9, 0.5) {$0.004$};
    \node at (2.8, -0.5) {……};

    \node at (7.0, 0.5) {$-16$};
    \node at (8.9, -0.5) {……};
\end{tikzpicture}
